Optical information recording/reproducing apparatus that produces

Abstract

An optical information recording and/or reproducing apparatus includes an irradiating device including an objective lens, having a curved surface, for irradiating a recording light beam to a magnetooptical recording medium having at least two magnetic layers, which are a recording layer and a reproduction layer, and which are exchanged-coupled to each other, and a magnetic layer for controlling the exchange-coupling force to block the exchange-coupling force between the recording and reproduction layers, a device for applying an external magnetic field modulated according to an information signal to be recorded on the beam irradiated portion of the recording medium to record information on the recording layer and to orient magnetization of the reproduction layer in a direction parallel to the external magnetic field, a splitting device including a polarizing beam splitter for splitting at least light produced by a magnetooptic effect of the recording medium and light produced by diffraction at the curved surface of the objective lens, a detector including a multi-divided photodetector for respectively detecting the split light beams and a device for producing verifying reproduction signals by executing a predetermined computation using detection signals of the detection surfaces of the photodetector.